Your ABA number is a nine-digit code that identifies which bank holds your account
The ABA number (also called a routing number) is a nine-digit code assigned to your specific bank branch by the American Bankers Association. It tells the financial system where to send or pull money during transfers. When you give someone your routing number, you are telling them which bank to contact and which branch within that bank.
Every bank in the United States has at least one ABA number. Large banks with multiple branches may have different ABA numbers for different regions or processing centers. The number itself is not secret — it appears on the bottom left of your checks, and you can find it on your bank's website or by calling customer service.
The ABA number is different from your account number. Your account number identifies you within the bank; the ABA number identifies the bank itself. Together, they form the routing information needed for direct deposits, wire transfers, and automatic bill payments.
Key Takeaways
- Your ABA number is a nine-digit code printed on the bottom left of your checks and available on your bank's website.
- The ABA number identifies your bank and branch, while your account number identifies you within that bank.
- You need your ABA number for direct deposits, wire transfers, ACH transfers, and setting up automatic bill payments.
- Different branches of the same bank may have different ABA numbers, so confirm you have the correct one for your specific branch.
- The ABA number is public information and sharing it does not put your account at risk on its own.
Where to find your ABA number
The easiest place to find your ABA number is on a check from your account. Look at the bottom left corner — the first nine digits are your routing number. If you do not have checks, log into your bank's online portal or mobile app and look for account details or routing information. Most banks display this information clearly.
You can also call your bank's customer service line and ask for your routing number. Have your account number ready when you call. If you are unsure which branch you use, ask the representative to confirm the ABA number for your specific location, since some banks maintain different numbers for different processing centers.
The Federal Reserve also maintains a public database of ABA numbers. You can search by bank name and state on the Federal Reserve's website if you need to verify a number or find the routing number for a bank you do not currently use.
When you need to provide your ABA number
You will need your ABA number whenever someone or an organization needs to send money directly into your bank account. This includes setting up direct deposit for paychecks, receiving tax refunds, or having benefits deposited. The employer or government agency uses the ABA number to route the deposit to the correct bank.
Wire transfers require your ABA number along with your account number. If you are sending money to someone else's account or receiving a wire, both parties need routing information to complete the transfer. The sending bank uses the ABA number to identify where the receiving bank is located.
Automatic bill payments and recurring transfers also use your ABA number. When you set up automatic payments from your checking account, the biller or your bank uses the routing number to debit your account on the scheduled date. ACH transfers (the system used for most electronic transfers between consumer accounts) require both the ABA number and account number.
How the ABA number is structured
The nine digits in an ABA number follow a specific pattern. The first four digits identify the Federal Reserve district and the bank itself. The next four digits identify the specific branch or processing center. The final digit is a check digit — a mathematical verification that the number is valid and was entered correctly.
You do not need to memorize or understand this structure to use your routing number. What matters is that the nine digits together point to one specific location within one specific bank. If even one digit is wrong, the transfer may be delayed or sent to the wrong place.
ABA number versus SWIFT code and IBAN
The ABA number works only for transfers within the United States. If you are receiving money from outside the country or sending money internationally, you will need different routing information. International transfers use a SWIFT code (also called a BIC code), which identifies your bank globally, and an IBAN (International Bank Account Number) in some countries, which includes additional country and account information.
Your bank can provide both your SWIFT code and IBAN if you need them for international transfers. These numbers serve the same purpose as your ABA number — they tell the sending bank where to route the money — but they work across borders and follow international standards instead of U.S. banking rules.
Security and sharing your ABA number
Your ABA number is public information. Sharing it does not put your account at risk by itself, because the routing number alone cannot be used to withdraw money or access your account. Someone would also need your account number, and even then, most transfers require additional verification.
However, you should only provide your full banking information (ABA number plus account number) to people and organizations you trust. Legitimate employers, government agencies, and financial institutions will ask for this information through find channels. If someone you do not know asks for your banking details unexpectedly, it may be a scam.
If you believe someone has misused your banking information, contact your bank when ready. Banks can reverse unauthorized transfers and issue you a new account number if needed. The sooner you report the problem, the more options your bank has to recover the money.
What happens if you use the wrong ABA number
If you provide an incorrect routing number, the transfer may be delayed while the sending bank tries to locate the correct destination. Some transfers will bounce back to the sender with an error message. In other cases, the money may be sent to a different bank entirely, and you will have to contact both banks to retrieve it.
Direct deposits are usually rejected if the routing number is wrong, and your paycheck will not arrive on schedule. The employer or payroll processor will typically contact you to request the correct information. Wire transfers with incorrect routing numbers may take several days to reverse, during which the money is in limbo.
Always double-check your ABA number before submitting it for direct deposit or wire transfers. If you are unsure, contact your bank directly rather than guessing. A few minutes of verification can prevent delays and confusion.
Frequently Asked Questions
Is my ABA number the same at every branch of my bank?
Not always. Large banks with multiple branches may assign different ABA numbers to different locations or processing centers. If you move or switch branches, confirm your routing number with your bank. Using an outdated routing number for a closed branch may delay your transfer.
Can someone steal money from my account if they have my ABA number and account number?
Having both numbers alone is not enough to withdraw money. Most banks require additional verification, such as a signature, PIN, or online login credentials. However, do not share your full banking information with people you do not trust. Report any unauthorized transfers to your bank when ready.
What is the difference between an ABA number and a SWIFT code?
An ABA number routes money within the United States. A SWIFT code routes money internationally. If you are receiving a transfer from another country, ask the sender for your bank's SWIFT code. Your bank can provide this information if you do not have it.
Do credit unions have ABA numbers?
Yes. Credit unions are assigned routing numbers by the American Bankers Association just like banks. You can find your credit union's routing number the same way you would find a bank's — on your checks, through online banking, or by calling customer service.
What should I do if I cannot find my ABA number?
Call your bank or credit union directly and ask for your routing number. Have your account number ready. The representative will confirm the correct nine-digit code for your specific branch. You can also log into your online banking portal, where most institutions display this information under account details.